Evaluation of longitudinal changes in choroidal thickness during pregnancy and postpartum using widefield swept-source optical coherence tomography

In this exploratory study, we investigated longitudinal changes in whole, luminal, and stromal choroidal thickness (CT) during pregnancy and the postpartum period using widefield swept-source optical coherence tomography. Ten eyes of five healthy pregnant women were examined monthly from mid-pregnancy to delivery and, when possible, at least 1 year postpartum. CT was measured over a 20 × 23 mm area centered on the fovea and was analyzed using a grid of three concentric subfields defined by circles measuring 3, 9, and 18 mm in diameter. At 5 months' gestation, the mean central CT was 258 ± 35 μm. For the right eye, the mean CT within the entire 18-mm circle showed a nonsignificant increase between 4 and 5 months of gestation (P = 0.078), followed by a significant decrease between 5 and 9 months (P = 0.038). After delivery, the choroid became thicker again, although this change was not statistically significant (P = 0.117). All subfields showed similar fluctuations. Thickness recovered partially postpartum, mainly reflecting changes in the luminal rather than in the stromal component. These findings suggest that pregnancy induces dynamic, reversible vascular changes in the choroid, which may reflect ocular adaptations to systemic circulatory alterations.